[Leica] math challenged

[philippe.amard at sfr.fr (Philippe Amard)]

 From another list

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Someone has a lot of time on their hands:

http://www.josephjamesphotography.com/equivalence/#Q&A

Pretty detailed. 


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Hope this brings to the confusion  ;-) 
Phx


      



H. Ball Arche wrote:

>"Yes, but the wides are the normals for the 1.3x crop, so you want the 
>wider VF."
>
>
>
>Whoa, you lost me.
>
>If a 50mm lens taking in a 40 degree wide field of view is considered 
>'normal' (Mark, forgive me) in 35mm photography, 
>then with a 1.3 crop factor, isn't a 35 going to take in approximately the 
>same 40 degree field of view?
>
>40 degrees is 40 degrees, regardless of the focal length of the lens that 
>is projecting that slice of space, and you adjust the VF magnification to 
>suit, which means going with a narrower (than 0.71) VF doesn't it? Don't 
>the 35's 'normal' framelines (40 degrees) float well in from the edges of 
>the M8's 0.68 VF? The M3's 0.91 VF has 40 degree wide framelines that 
>pretty much fill the window. 
>
>I went to the Leica site looking to see if they had a series of frameline 
>views for the M8 like they have for the ala carte options for the MP/M7 but 
>couldn't find anything.
>
>
>
>
>----- Original Message ----
>From: Richard Man <richard.lists at gmail.com>
>To: Leica Users Group <lug at leica-users.org>
>Sent: Saturday, September 5, 2009 2:44:36 PM
>Subject: Re: [Leica] math challenged
>
>Yes, but the wides are the normals for the 1.3x crop, so you want the wider 
>VF.
>
>It really only matters regarding focusing accuracy, and with the 1.3x
>crop, you get more DoF on the same aperture, so the lower mag factor
>is canceled out. Certainly you see people shooting F1 all day long on
>the M8 with spot on focus so the RF/VF is not an issue in that regard.
>
>On Sat, Sep 5, 2009 at 12:22 PM, H. Ball Arche<h_arche at yahoo.com> wrote:
>  
>
>>OK, so I just learned that the M8's have a 0.68 VF. My question is, what 
>>does that translate into, relative to the crop factor of that sensor?  In 
>>other words, is it like what an approximately 0.45 VF would show you on a 
>>FF camera?
>>
>>Since 0.72 has been the 'standard' VF since the M2, I'd have figured that 
>>in the M8 they would want to reproduce the same relative field of view, 
>>lens for lens, narrowing it appropriately.
>>
>>If I'd've bothered to wonder about it I would have figured the M8 VF to be 
>>0.86, or 0.91 like the M3 - something narrower than 0.72.
>>
>>The 0.68 field of view VF in the M8 must REALLY favor the wides, taking in 
>>a much broader field of view than would the 0.58 VF with the same lens on 
>>a full frame camera.
>>
>>    
>>
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